JP2010174718A - Electric blower and vacuum cleaner using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric blower for a vacuum cleaner including an impeller having a sufficient fastening force and equipped with an enhanced blowing efficiency. <P>SOLUTION: The structure is composed of a front face shroud 2 made in metal sheeting, a rear face shroud 3 made in metal sheeting, and a plurality of blades 4 in metal sheeting each having a caulked projection 5 and arranged between the two shrouds 2 and 3, and the impeller 1 of this electric blower is formed by engaging the caulked projection 5 with fitting holes 6 provided in the shrouds 2 and 3 and then integrating through a caulking process, wherein the thickness of the main passage part 7 of each blade 4 is smaller than the plate thickness of the caulked projection part 5, at least in the range from the projection part 5 to the periphery of the blade 4, while the section shape of the blade 4 is formed symmetric about the direction across the plate thickness, at least in the caulked projection part 5. Accordingly the peripheral end of the blade 4 can be thinned which assures enhancement of the blowing performance, and the plate thickness of the caulked projection part 5 is secured to a predetermined level or above free of the risk to have breakage caused by the centrifugal force, and further deformation and/or distortion in the caulking process is suppressed, whereby a high fastening force is obtained with high precision. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric blower that improves air blowing efficiency and assembly strength of an impeller, and a vacuum cleaner using the same.

  Conventionally, as an electric blower for improving the blowing efficiency of this type of impeller, there has been one shown in FIGS. 11 to 14 (see, for example, Patent Document 1).

  FIG. 11 is a half cross-sectional view of the conventional electric blower described in Patent Document 1, FIG. 12A is a cross-sectional view showing a state before assembly processing of the impeller of the electric blower, and FIG. FIG. 12C is a cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade, and FIG. 13 is a state after assembly processing of the impeller. FIG. 14 is a plan view showing the impeller of the electric blower with a part cut away.

  11 to 14, a conventional electric blower 9 includes an impeller 1, an air guide 13 having a plurality of stationary blades 11 and a substrate 12 positioned on the outer periphery of the impeller 1, and the impeller 1 together with the air guide 13. A casing 16 having an intake hole 15 facing the inlet portion 14 of the impeller at the center and an electric motor 17 for rotating the impeller 1 are provided.

  The impeller 1 includes a sheet metal front shroud 2, a sheet metal rear shroud 3, and a plurality of sheet metal blades 4 disposed between both sheet metal front and rear shrouds 2 and 3.

  Further, the sheet metal rear shroud 3 of the impeller 1 is fixed to the rotating shaft 18 of the electric motor 17 with a nut 20 via a washer 19.

  Each sheet metal blade 4 has a plurality of caulking projections 5, and these caulking projections 5 are fitted into caulking fitting holes 6 provided in the sheet metal front and rear shrouds 2 and 3. It is integrated by caulking.

  Here, since the sheet metal blade 4 is generally punched from a sheet material of the same thickness and bent into a curved shape, the sheet metal blade is at all positions A, B, and C in FIG. The plate thicknesses of the main flow path portion 7 and the caulking projection portion 5 are substantially equal (FIG. 12B).

In addition, there is a configuration in which an inclined portion cut obliquely is provided on the outer peripheral end surface of the sheet metal blade 4 by using additional press processing or cutting processing to suppress generation of operation sound due to airflow disturbance (for example, Patent Document 2). reference).
JP-A-2-19696 JP 2000-27797 A

  The plate thickness at the outer peripheral end of the sheet metal blade 4 is thick, and the airflow is disturbed by the separation at the outer periphery of the impeller 1 and the wall surface friction at the outer peripheral end surface of the sheet metal blade 4 is generated, making it difficult to ensure high blowing performance. Moreover, even if only a part of the outer peripheral edge of the sheet metal blade 4 is cut obliquely to suppress the turbulence of the airflow, it is difficult to ensure the air blowing performance even if the increase in the operation sound can be prevented.

However, in the configuration of the impeller 1 of the conventional electric blower, when the outer peripheral end of the sheet metal blade 4 is thinned, the thickness of the caulking protrusion inevitably decreases, and the front and rear shrouds 2, 3 made of sheet metal are caulked. And the sheet metal blade 4 cannot be firmly fastened.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an electric blower having a sufficient fastening force by caulking and an air blower that improves the blowing performance by extremely reducing the thickness of the outer peripheral edge of the sheet metal blade and uses the same. The purpose is to provide a vacuum cleaner.

  In order to solve the above-described conventional problems, an electric blower of the present invention includes a sheet metal front shroud, a sheet metal rear shroud, and a plurality of sheet metal blades each having a caulking projection and disposed between the shrouds. And an impeller that is integrated by caulking after engaging the caulking protrusions with the fitting holes provided in the shrouds, and the thickness of the main flow path portion of the sheet metal blade is at least the caulking. From the protrusion to the outer periphery of the sheet metal blade, it is thinner than the plate thickness of the caulking protrusion, and the cross-sectional shape of the sheet metal blade is at least symmetrical in the sheet thickness direction at the caulking protrusion, The thickness of the sheet metal blade is extremely thin in most areas including the outer edge of the sheet metal blade, and as a result, the outer edge of the sheet metal blade is smoothly thinned. In addition to improving the air blowing performance, the plate thickness of the caulking projections can be secured above a certain level where damage due to centrifugal force does not occur, and the sheet metal blade can be deformed or distorted during caulking. In this way, a high fastening force can be obtained with high accuracy.

  In addition, by reducing the thickness of the sheet metal blade, the impeller can be reduced in weight.

  Further, by reducing the thickness of the outer peripheral edge of the sheet metal blade, it is possible to suppress the occurrence of aerodynamic noise by suppressing the occurrence of turbulence due to peeling and the generation of minute vortices. Furthermore, since it is caulked with high accuracy, the variation in the outer peripheral position of each sheet metal blade is reduced, the interference sound with the diffuser is reduced, the unbalance amount with respect to rotation is reduced, and the vibration noise is also reduced. is there.

  In addition, due to strong fastening, reduction of unbalance amount, weight reduction, etc., high-speed rotation is possible and air blowing capacity can be improved.

  Moreover, the vacuum cleaner of this invention has the electric blower of any one of Claims 1-7, and its attraction | suction performance is high and can perform comfortable cleaning.

  The electric blower of the present invention and the vacuum cleaner using the electric blower can sufficiently improve the blowing efficiency and can obtain a sufficient fastening force of the impeller itself.

The first invention comprises a sheet metal front shroud, a sheet metal rear shroud, and a plurality of sheet metal blades each having a caulking projection and disposed between the shrouds, and the fittings provided on both shrouds. An impeller that is integrated by caulking after the caulking protrusion is engaged with the hole is provided, and the plate thickness of the main flow path portion of the sheet metal blade is at least from the caulking protrusion to the outer periphery of the sheet metal blade The sheet metal blade is thinner than the plate thickness of the caulking projection, and the cross-sectional shape of the sheet metal blade is at least symmetrical in the plate thickness direction at the caulking projection, and the sheet metal blade including the outer edge of the sheet metal blade In most areas, the sheet thickness is extremely thin, and as a result, the outer edge of the sheet metal blade can be smoothly thinned to improve the blowing performance. The plate thickness of the caulking protrusions can be kept above a certain level where damage due to centrifugal force does not occur, and the sheet metal blade can be prevented from being obliquely deformed or distorted during caulking to obtain high fastening force with high accuracy. It is something that can be done.

  In addition, by reducing the thickness of the sheet metal blade, the impeller can be reduced in weight.

  Further, by reducing the thickness of the outer peripheral edge of the sheet metal blade, it is possible to suppress the occurrence of aerodynamic noise by suppressing the occurrence of turbulence due to peeling and the generation of minute vortices. Furthermore, since it is caulked with high accuracy, the variation in the outer peripheral position of each sheet metal blade is reduced, the interference sound with the diffuser is reduced, the unbalance amount with respect to rotation is reduced, and the vibration noise is also reduced. is there.

  In addition, due to strong fastening, reduction of unbalance amount, weight reduction, etc., high-speed rotation is possible and air blowing capacity can be improved.

  In the second invention, in particular, the cross-sectional shape of the sheet metal blade of the first invention is constituted by a curved surface from the caulking protrusion to the main flow path of the sheet metal blade at least in the caulking protrusion. The stress applied to the boundary between the caulking projection during caulking and the main flow path of the sheet metal blade can be reduced, and deformation during processing can be suppressed.Furthermore, both shrouds and each sheet metal blade can be By making the flow path shape in the vicinity of the joint close to the curved pipe, it is possible to reduce the loss due to the generation of the secondary flow and improve the blowing performance.

  In the third invention, in particular, the cross-sectional shape of the sheet metal blade of the first or second invention is such that only the caulking projection is symmetric, and the cross-sectional shape of the other part is asymmetrical. In the flow path, the degree of change in the flow velocity between the shrouds can be suppressed to a small level, and turbulence due to the generation of large vortices and separation can be suppressed to improve the blowing performance.

  According to a fourth aspect of the invention, in particular, a plurality of caulking protrusions of each sheet metal blade according to any one of the first to third aspects are provided in each shroud direction, and at least one of the caulking protrusions is the caulking protrusion. The plate thickness of the main flow path portion of the sheet metal blade is thicker than the thickness of the plate portion, and after the caulking projection portion having this thick plate thickness is caulked, the remaining caulking projection portion is caulked. As a result, the positioning accuracy between the shrouds and the respective sheet metal blades is improved, the processing accuracy is improved, and the plate thickness of the main flow path portion of the sheet metal blade is more than the plate thickness of the caulking projections. In the thin area, both the shroud and each sheet metal blade are already in contact with each other, not just the caulking projections, but the entire sheet metal blade. While subjected to caulking, thereby improving the machining accuracy.

  In the fifth aspect of the invention, in particular, the distance between the shrouds of any one of the first to fourth aspects of the invention is at least the same or monotonously increased from the caulking projection portion arranged on the outermost circumferential side toward the outer circumferential direction. In the caulking process, near the caulking projection between both shrouds, from the outer periphery of the impeller toward the impeller internal flow path, the strength of the caulking projection after the completion of caulking is equal to the height of the sheet metal blade. A jig can be temporarily inserted and reinforced, and processing can be performed with high accuracy and processing speed can be improved.

  In the sixth invention, in particular, the size of the fitting holes provided in both shrouds according to any one of the first to fifth inventions is such that, in the thickness direction, the caulking projection portion is closer to the tip end side of the caulking projection. It is larger than the protrusion root side of the protrusion, and the stress on both shrouds is dispersed while the caulking protrusion is crushed during the caulking process, and further, the force during caulking process is distributed from the shroud to the entire sheet metal blade. The shape of the main flow path portion of the blade made of the blade is not inadvertently deformed, and the processing accuracy can be improved.

In addition, since the caulking protrusion is smoothly deformed and buried in the fitting hole, it is possible to reduce the gap between the two and reduce the leakage loss. Further, the caulking protrusion protrudes from the shroud to the outside of the impeller. It is possible to reduce the rotating disk friction loss by reducing the size.

  In the seventh invention, in particular, the fitting holes provided in both the shrouds of the sixth invention have a step portion between the projection tip side of the caulking projection and the projection root side of the caulking projection in the thickness direction. With this, the force during caulking is more reliably distributed to both shrouds, and the machining accuracy can be improved.

  An electric vacuum cleaner according to an eighth aspect of the invention has the electric blower according to any one of claims 1 to 7, has high suction performance, and can be cleaned comfortably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The electric blower in Embodiment 1 of this invention is demonstrated using FIGS. FIG. 1A is a schematic cross-sectional view showing a state before assembly processing of the impeller 1 of the electric blower according to the present embodiment, and FIG. FIG. 1C is a cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade, FIG. 2 is a schematic cross-sectional view showing a state after assembly processing of the impeller 1, and FIG. FIG. 2 is a plan view showing the impeller with a part cut away. In addition, about the same part as the said conventional electric blower, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The electric blower 9 in the present embodiment includes the impeller 1, an air guide 13 that is located on the outer periphery of the impeller 1 and includes a plurality of stationary blades 11 and its substrate 12, and the impeller 1 together with the air guide 13. A casing 16 having an intake hole 15 facing the inlet portion 14 of the impeller 1 and an electric motor 17 for rotating the impeller 1 are provided.

  1 to 3, the impeller 1 includes a sheet metal front shroud 2, a sheet metal rear shroud 3, a plurality of sheet metal blades 4 disposed between the shrouds 2 and 3, and a crimping provided on the sheet metal blade 4. The projection 5 and the shrouds 2 and 3 are provided with a fitting hole 6 that engages with the caulking projection 5, and the sheet metal blade 4 and the shrouds 2 and 3 are integrated by caulking. The sheet thickness of the main flow path portion 7 of the sheet metal blade 4 is smaller than the sheet thickness of the caulking projection 5 at least from the caulking projection 5 to the outer peripheral portion 10 of the sheet metal blade 4. Furthermore, the cross-sectional shape of the sheet metal blade 4 is symmetrical in the plate thickness direction at least in the caulking projection 5 (positions A, B, C and FIGS. 1B and 1C).

  Here, as shown in FIG. 1 (a), the two shrouds 2 and 3 which are separate parts and a plurality of sheet metal blades 4 are temporarily assembled as shown in FIG. 1 (b), and then a caulking press is used. Then, the tip of the caulking protrusion 5 is crushed through a dedicated jig to perform caulking (FIG. 1 (c)).

  About the electric blower 9 in this Embodiment comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  2 and 3, the impeller 1 fixed to the rotating shaft 18 of the electric motor 17 rotates at high speed (in the direction of arrow D), sucks air from the inlet portion 14 (see FIG. 11) of the impeller 1, and the air flow is The front shroud 2, the rear shroud 3, and the internal flow passage 21 surrounded by the two adjacent sheet metal blades 4 pass through and are discharged from the outer periphery of the impeller 1.

The air flow discharged from the impeller 1 passes between the stationary blades 11 of the air guide 13 and then passes while cooling the inside of the electric motor 17, and the electric motor 9 passes through an exhaust hole (not shown) provided in the electric motor 9. It is discharged outside.

  At this time, the plate thickness is made extremely thin in the most range of the sheet metal blade 4 including the outer peripheral end of the sheet metal blade 4, and as a result, the outer peripheral end of the sheet metal blade 4 can be smoothly thinned and the air blowing performance is improved. In addition, the sheet thickness of the caulking projection 5 can be secured to a certain thickness that does not cause damage due to centrifugal force, and the sheet metal blade 4 is prevented from being obliquely deformed or distorted during caulking, with high accuracy. A high fastening force can be obtained.

  Further, the impeller 1 can be reduced in weight by reducing the thickness of the sheet metal blade 4.

  Further, by reducing the plate thickness at the outer peripheral end of the sheet metal blade 4, it is possible to suppress the occurrence of aerodynamic noise by suppressing the occurrence of turbulence due to peeling and the generation of minute vortices. Furthermore, since it is caulked with high accuracy, the variation in the outer peripheral position of each sheet metal blade 4 is reduced, the interference sound with the air guide 13 and the like is reduced, the unbalance amount with respect to the rotation is reduced, and the vibration noise is also reduced. Is.

  In addition, due to strong fastening, a reduction in unbalance amount, weight reduction, and the like, high-speed rotation is possible and air blowing capacity can be improved.

  Next, another configuration example of the impeller 1 will be described with reference to FIG. 4A is a cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller, and FIG. 4B is a cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade.

  In this configuration example, as shown in FIGS. 4A and 4B, the two shrouds 2 and 3 which are separate parts and a plurality of sheet metal blades 4 are temporarily assembled (FIG. 4A), and thereafter Using a caulking press machine, the tip of the caulking projection 5 is crushed by a dedicated jig to perform caulking processing (FIG. 4B). Here, the cross-sectional shape of the sheet metal blade 4 is at least caulking projection 5, a curved portion is formed from the caulking protrusion 5 toward the main flow path portion 7 of the sheet metal blade 4, and a boundary portion between the caulking protrusion 5 during the caulking process and the main flow path portion 7 of the sheet metal blade 4. The stress applied to 22 can be reduced, the deformation during processing is suppressed, and the flow path shape in the vicinity of the joint 23 between the shrouds 2 and 3 and each sheet metal blade 4 in the internal flow path 21 of the impeller 1 is bent. This reduces the loss due to secondary flow generation. One in which it is possible to improve the wind performance.

  Further, as shown in FIGS. 5A and 5B, the cross-sectional shape of the sheet metal blade 4 is a symmetrical shape only in the caulking protrusion 5, and the cross section of the other part excluding the caulking protrusion 5 of the sheet metal blade 4. If the shape is an asymmetric shape, the degree of change in the flow velocity between the shrouds 2 and 3 in the inner flow path 21 of the impeller 1 can be suppressed to a small level, and the turbulence due to the generation of large vortices and separation can be suppressed to improve the blowing performance. It can be improved.

  Here, FIG. 5A is a cross-sectional shape of the sheet metal blade 4 as viewed from the outer peripheral side, and the rear shroud 3 side is arranged rearward from the front shroud 2 side with respect to the rotation direction (arrow E direction). In addition, the occurrence of peeling is suppressed by shifting the position where the air is blown to the outer periphery of the impeller 1 between the shrouds 2 and 3. In FIG. 5B, the central portion 24 of the main flow path portion 7 of the sheet metal blade 4 is arranged rearward with respect to the rotation direction (arrow E), and the same effect is obtained.

6 (a), 6 (b), and 6 (c), a plurality of caulking protrusions 5 in each sheet metal blade 4 are provided in each shroud 2 and 3 directions, and at least one of the caulking protrusions 5 is provided. (In this case, one place on the innermost peripheral side) is a sheet metal blade 4 compared to the plate thickness of the caulking protrusion 5.
After the caulking projection 5a (position A and FIG. 6B) having the thick plate thickness is caulked, the remaining caulking projection 5b (position B) is formed. , C and FIG. 6 (c)), the positioning accuracy between the shrouds 2 and 3 and the respective sheet metal blades 4 is improved, and the processing accuracy is improved, and the sheet metal is made. At locations where the plate thickness of the main flow path portion 7 of the blade 4 is thinner than the plate thickness of the caulking projection 5, both the shrouds 2, 3 and the respective sheet metal blades are already applied not only to the caulking projection 5 but also to the entire sheet metal blade 4. 4 is almost in contact with each other, and it is possible to improve the processing accuracy by performing the caulking process while dispersing the caulking process force on the entire sheet metal blade 4.

  Further, as shown in FIGS. 7 (a) and 7 (b), the distances are the same from the caulking projection 5c disposed at least on the outermost peripheral side of the shrouds 2 and 3 toward the outer peripheral direction (FIG. 7 (a). )) Or monotonously increasing (FIG. 7 (b)), during the caulking process, in the vicinity of the caulking projection 5 of the sheet metal blade 4 between the shrouds 2 and 3, from the outer periphery side of the impeller 1 to the inside of the impeller A high-strength jig 25 equivalent to the height of the sheet metal blade 4 of the caulking projection 5 after the caulking process is completed can be temporarily inserted and reinforced toward the flow path 21, and can be processed with high accuracy. At the same time, the processing speed can be improved.

  Next, another configuration example of the impeller 1 will be described with reference to FIG. 8A is a cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller, FIG. 8B is a cross-sectional view showing a state in the vicinity of the sheet metal blade during assembly processing, and FIG. c) is a cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade.

  In the present configuration example, as shown in FIG. 8, the size of the fitting hole 6 provided in both the shrouds 2 and 3 on the protrusion tip 26 side of the caulking protrusion 5 in the plate thickness direction is the caulking protrusion 5. In the caulking process, the stress on the shrouds 2 and 3 is dispersed while the caulking protrusion 5 is crushed (FIG. 8 (b)). Since the force during caulking is distributed from the shrouds 2 and 3 to the entire sheet metal blade 4, the shape of the main flow path portion 7 of the sheet metal blade 4 is not inadvertently deformed, and the processing accuracy can be improved.

  Further, since the caulking protrusion 5 is smoothly deformed and buried in the fitting hole 6, it is possible to reduce the gap between the fitting hole 6 and the caulking protrusion 5, thereby reducing leakage loss. It is possible to reduce the rotating disk friction loss by reducing the size of the caulking projection 5 protruding from the shrouds 2 and 3 to the outside of the impeller 1.

  Next, another configuration example of the impeller 1 will be described with reference to FIG. 9A is a cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller, FIG. 9B is a cross-sectional view showing a state in the vicinity of the sheet metal blade during assembly processing, and FIG. c) is a cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade.

  In this configuration example, as shown in FIG. 9, the fitting holes 6 provided in both shrouds 2 and 3 are inserted between the projection tip 26 side and the projection root 27 side of the caulking projection portion 5 in the plate thickness direction. In addition, since the step portion 28 is provided, the force during the caulking process is reliably distributed to the shrouds a few (FIG. 9B), and the machining accuracy can be further improved.

  Although not particularly illustrated, a plurality of curved guide vanes (usually the same number as the sheet metal blade 4 or an integral number thereof) and a chevron are formed in the inlet portion 14 (air suction port) of the impeller 1. If the inducer part which has a hub is provided, the peeling loss etc. by the bending in the inlet part 14 of the impeller 1 can be reduced, and ventilation performance can be improved more.

In addition, when manufacturing an inducer mainly with a resin material, it is desirable that there is no level | step difference and a clearance gap in the connection part connected to the blade 4 made from a sheet metal from the guide blade of an inducer.

  For this purpose, an insertion groove for inserting a thin sheet metal blade 4 is provided on the resin-made inducer side, or the sheet metal blade 4 is forcibly pressed into the inducer side to perform crimping. It is possible to improve the air blowing performance by reducing the steps and gaps between them.

(Embodiment 2)
FIG. 10 is a schematic cross-sectional view showing a schematic configuration of the electric vacuum cleaner according to Embodiment 2 of the present invention.

  As shown in FIG. 10, the electric vacuum cleaner in the present embodiment is provided with the electric blower 9 described in the above embodiment in the vacuum cleaner main body 29, and the suction force from the electric blower 9 causes the suction nozzle 30 to The dust on the floor surface is sucked together with the air flow, and the dust is stored in the dust collecting chamber 31.

  As described above, according to the present embodiment, by using the electric blower 9 excellent in air blowing performance, it is possible to realize a vacuum cleaner that is excellent in suction performance and further reduces energy consumption.

  As described above, the electric blower according to the present invention can sufficiently improve the blowing efficiency, and can be widely applied not only as a vacuum cleaner but also to other household appliances, industrial equipment, and the like. . Furthermore, the electric blower can be applied to a compressor, a turbine, and a liquid pump from the same viewpoint.

(A) Schematic sectional view showing a state before assembly processing of the impeller of the electric blower in Embodiment 1 of the present invention (b) Cross sectional view showing a state before assembly processing in which the sheet metal blade of the impeller and both shrouds are temporarily assembled ( c) Sectional view showing the state after assembly near the sheet metal blade Schematic sectional view showing the impeller after assembly processing Plan view showing the impeller with a part cut away (A) Cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller (b) Cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade (A) Cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller (b) Cross-sectional view showing a state after assembly processing in the vicinity of the sheet metal blade (A) Schematic sectional view showing a state before assembly processing of another impeller (b) Cross sectional view showing a state before assembly processing in the vicinity of the impeller sheet metal blade (c) State before assembly processing in the vicinity of the impeller sheet metal blade Cross section (A) Schematic sectional view showing a state before assembly processing of another impeller (b) Schematic sectional view showing a state before assembly processing of another impeller (A) Cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller (b) Cross-sectional view showing a state in the vicinity of the sheet metal blade during assembly processing (c) State after assembly processing in the vicinity of the sheet metal blade Cross section showing (A) Cross-sectional view showing a state before assembly processing in the vicinity of a sheet metal blade of another impeller (b) Cross-sectional view showing a state in the vicinity of the sheet metal blade during assembly processing (c) State after assembly processing in the vicinity of the sheet metal blade Cross section showing Schematic sectional view showing a schematic configuration of the electric vacuum cleaner according to Embodiment 2 of the present invention. Half sectional view of a conventional electric blower (A) Cross-sectional view showing the state before assembly processing of the impeller of the electric blower (b) Cross-sectional view showing the state before assembly processing in the vicinity of the sheet metal blade of the impeller (c) State after assembly processing in the vicinity of the sheet metal blade Cross section shown Schematic sectional view showing the impeller after assembly processing Top view showing the impeller of the electric blower with a part cut away

DESCRIPTION OF SYMBOLS 1 Impeller 2 Sheet metal front surface shroud 3 Sheet metal rear surface shroud 4 Sheet metal blade 5 Caulking projection part 6 Fitting hole 7 Main flow path part 9 Electric blower 10 Outer peripheral part 25 Jig 26 Projection tip 27 Projection base 28 Step part

Claims (8)

A sheet metal front shroud, a sheet metal rear shroud, and a plurality of sheet metal blades each having a caulking protrusion and disposed between the two shrouds, and the caulking protrusions in fitting holes provided in the shrouds. An impeller that is integrated by caulking after the engagement, and the plate thickness of the main flow path portion of the sheet metal blade is at least from the caulking protrusion portion to the outer peripheral portion of the sheet metal blade. An electric blower characterized in that the sheet metal blade has a cross-sectional shape that is symmetric in the plate thickness direction at least in the caulking projections. 2. The electric blower according to claim 1, wherein the cross-sectional shape of the sheet metal blade is a curved surface from at least the caulking protrusion toward the main flow path of the sheet metal blade at least in the caulking protrusion. 3. The electric blower according to claim 1, wherein a cross-sectional shape of the sheet metal blade is a symmetric shape only in a caulking projection, and a cross-sectional shape of another portion is an asymmetric shape. A plurality of caulking protrusions of each sheet metal blade are provided in each shroud direction, and at least one of the caulking protrusions has a plate thickness of the main flow path portion of the sheet metal blade compared to the plate thickness of the caulking protrusion. The caulking projection having a thick plate thickness and the caulking projection having the thick plate thickness is caulked, and then the remaining caulking projection is caulked to be completed. Electric blower. The electric blower according to any one of claims 1 to 4, wherein an interval between the shrouds is set to be the same or monotonously increased from a caulking projection portion arranged at least on the outermost peripheral side toward an outer peripheral direction. The size of the fitting hole provided in both shrouds is as defined in any one of claims 1 to 5, wherein the protrusion tip side of the caulking protrusion is larger than the protrusion root side of the caulking protrusion in the thickness direction. The electric blower described. The electric blower according to claim 6, wherein the fitting holes provided in both shrouds have a step portion between a protrusion tip side of the caulking protrusion and a protrusion root side of the caulking protrusion in the thickness direction. The vacuum cleaner which has an electric blower of any one of Claims 1-7.

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